Database Schema Database schema--is the logical structure of the database. ■ Database instance--is a snapshot of the data in the database at a given instant in time. Example: ·schema: instructor(ID,name,dept name,salary) ·Instance: ID name dept name salary 22222 Einstein Physics 95000 12121 Wu Finance 90000 32343 El Said History 60000 45565 Katz Comp.Sci. 75000 98345 Kim Elec.Eng. 80000 76766 Crick Biology 72000 10101 Srinivasan Comp.Sci. 65000 58583 Califieri History 62000 83821 Brandt Comp.Sci. 92000 15151 Mozart Music 40000 33456 Gold Physics 87000 76543 Singh Finance 80000 Database System Concepts-7th Edition 2.7 @Silberschatz,Korth and SudarshanDatabase System Concepts - 7 2.7 ©Silberschatz, Korth and Sudarshan th Edition Database Schema ▪ Database schema -- is the logical structure of the database. ▪ Database instance -- is a snapshot of the data in the database at a given instant in time. ▪ Example: • schema: instructor (ID, name, dept_name, salary) • Instance: